When I was ten a friend of mine was a real original. A deaf entrepreneur. He would photocopy photos from his older brother’s Fangoria issues and sell the clippings to neighborhood kids. Trying to budge him on the prices was intimidating because he had to negotiate with his facial features. The teen brother was cool too (hey, he collected Fango) and one day showed me some artwork he had quickly drawn. It was a poster concept for a FRIDAY THE 13TH PART 8: TOXIC TERROR. It depicted an unmasked Jason with flesh warped by toxic waste and a cartoonishly gaping maw. I was impressed. The thing was, though, the year was 1988, FRIDAY THE 13TH PART VII was a current release and the real part 8, JASON TAKES MANHATTAN, featuring a toxic waste scarred Jason Voorhees in its climax, was yet to be made. A few years ago I thought back to that episode and recreated the drawing.
Not every idea can be synthesized. We have thousands of thoughts a day. Us creative types can imagine a hundred concepts a day. But where do all these ideas go to die? Up in a vapor cloud in some ethereal place. The same cloud everyone has subconscious access too. This is why you see films or books with similar concepts in develop in parallel.